A conventional navigation device displays a tunnel in a form different from that in which roads are displayed on a map while a vehicle equipped with the navigation device is traveling through the tunnel. However, because the remaining distance of the tunnel is not displayed on the map, the driver may have an uncertain, insecure feeling resulting from being unable to know information about the distance to the tunnel exit while the vehicle is traveling through a long tunnel.
As a technology of outputting information about a tunnel, patent reference 1 discloses a navigation device that can notify the driver about a relationship between the current position and an evacuation route promptly when the driver encounters an accident or the like in a tunnel. When the driver encounters an accident or the like in a tunnel, this conventional navigation device detects the emergency situation, such as an accident, according to the user's command or automatically, and informs the relationship between the current position and an emergency exit to the user.